Electrical snap-switch.



UNITED sTATEs PATENT oEErpE `C:HlRIS1.`I5LI.\T F, PAUL, OF PEEKSKILL, NEW YORK.

ELECTRICAL SNAP-SWITCH.

To (IU @710m 'it may concern.'

'Be it known that I, CHRISTIAN F. PAUL, a citizen of-the United States, residing at Peekskill, county of lllestcliestei, and of 1New Yorkl have invented certain new and useful yIn provements in Electrical Snap-Switches, o-f which the following is a full, clearand exact description.

This invention relates to so-called snap switches7 for electric circuits, and its chief object is to provide a switch which will operate with certainty under the most severe conditions of use and which can be subject- "led to rough usage of the most eXtreme character Without injury to its mechanism.

T o this and other ends the invention consists in the novel `features of construction and combinations of elements hereinafter described, and more particularly' set forth in the appended claims.

One form of the invention is illustrated in the accompanying drawings, in which:

Figure 1 is a plan view of my improved snap switch, moved. Fig. 2 isa longitudinal section on line 2 2 of Fig. 1. Fig. 3 is a view partly in section on line 3,3 of Fig. 2. Fig. e is a detail view of the ratchet employed to permit movement of the contact buttons in one direction only.

The casing 10 which incloses and protects the contact buttons and affords bearings for the shaft on which the buttons are mounted,

, is in the form of a flat box, rectangular in y pipe, the necks 15,

plan and having a removable cover 11 secured by bolts 12. On opposite sides the box is formed with tapering extensions 13, 111 terminating in tubular necks 15, 16, through which the electric conductors are led to the terminals inside. 1f the conductors outside the casing are inclosed in a conduit, as for example a waterproof hose- 16 can be inserted linto thevends of the hose, thereby making a water-tight joint Aand preventing entrance of water` and foreign matter. To give a. firm grip on the inside of the hose the necks may se corrugated on the outside, as shown. The cover 11 also makes a hermetic :joint with the casing, either by means of a suitable gasket (not shown) or by accurate fitting of the contacting edges.

On the inside of the box or casing 10 at the corners thereof are four lugs or bosses 17, on which are mounted two transverse bars 18, 19, of insulating material, fastened with the cover of the casing re- Specification of Letters Patent.

Statel `said element being composed. in

Patented Dec. 23, 1 91.3.

Application led October 15, 1912. Serial No. 725,840.

to their supporting bosses by screws Q0. These bars constitute insulating supports or bridges on which are mounted the terminals of the switch. 22, are mounted on the .insulating bars or supports 1S, 1l), respectively, by means of binding bolts Q3, Q41, which also serve as binding posts for the inner ends of the conductors. as will be readily understood. '.lhem;

terminals themselves are made of strips of spring sheet-metal bent in the Zig-zag form shown and extend inwardlyv from their supporting bars. vThe form of terminal described is advantageous for the reason that they can be made stift' enough to permit only very slightlexure vertically (as viewed in Fig.

2) Yand yet have ample yielding movement toward and from the inslllating bars 1S, 1).

The maximum yielding movement relatively to the bars 18, 19, with minimum flexure vertically, is obtained by giving the springs a lobe-like form at the bends. las clearly shown in Fig. Q.- rl`he tern'linals 21 are secured on the under side, and the terminals Q2 on the upper side, of their respective supports, as shown in Fig. 2.

Midway between the terminals 21, 2Q and parallel to the insulating terminal-supports.

1S, 19 Yis a shaft Q5 jouri'ialed at one end in 85 a sleeve 2G which is itself rotatably mount` ed in the adjacent casing wall. On this shaft the contact element is loosely mounted, the present instance, of Contact buttons 27, on a tube 25fl square in cross section', shown.

The contact buttons 27, 8, composing the contact element, are oval or elliptical in form with pointed ends, as shown, and are provided, each on one side, plates Q9, 30; the plates being on the alternateopposite sides of the successive buttons, that is, on the left-'hand sides of buttons 28 and on the right-,hand sides of buttons 27 as viewed in Fig.,1. ranged in pairs. with the Contact plates connected electrically, as indicated by the short diagoijial lines 31 in Fig. 1, and are separated by insulating disksI and at the ends of the series are the two From the foregoing it will be apparentthat with the buttons inthe position' in Figs. 1 and Q, the terminals on opposite sides of the buttons are electrically connected, and that if the buttons insulating faces will be brought into engagement with theterminals thusy breaking the The switch terminals 21, 60

Q8, mounted with contact 95 The buttons are arinsulating'disks 33. .105

be turned'half way around the '110 connection. The switch-illustrated is designed for a three-phase circuit and hence' has three pairs of buttons and three pairs of terminals, but of course the precise number of such parts used is immaterial to the invention. As will be seen inFig. 2, the elliptical or oval contact element in rotating with the shaft 25 has a camming action on the spring` terminals; and that the rotary movement ot the buttons is opposed b y the terminals until such movement exceeds 90O (from the neutral position) but is aided by the terminals from thatpoint on. Hence, to open the circuit it is only necessary to turn the buttons slightly past the F dead center so to speak, whereupon the terminals instantly snap the buttons on to the neutral position, Il. the buttons are turned less than 900 the terminals tend to snap them back to the initial position. Theoretically, it' the buttons are turned just to the dead center, or 900 past the neutral point, the tern'iinalsl have no tendency to turn them in either direction; but with the buttons pointed, as .showin and with terminals ot suitable stiffness. it is practically impossible to turn the buttons exactly to the dead center., no more or no less. Nloreover, the contact plates do not cover the Whole half-face of their buttons but at one end terminate short of the point, as shown in Fig. 2. Consequently if the buttons are turned far enough from the open-circuit position to bring the contact plates into engagement with the terminal-faces the points of the buttons will be past the dead center and Will therefore be snapped on to the closed-circuit position; and it means are provided to permit this forward rotation to the closed-circuit position independently of the handle by which the buttons are turned it Will be impossible to bring,r the Contact plates just in engagement with the terminals and hold them there and in that way make a poor connection. For this purpose the linger-button 81 outside the casing at the end of the shaft 25 is not connected to the shaft directlyA but to the sleeve 2G. The latter carries at -its inner end a ratchet Wheel 35, provided with arc-shaped slots 36, 37, extending in opposite directions 90 from the dead-center line o1 the buttons; the relation of the position ot the slots to the contact buttons and plates being illustrated in Fig. 4, in which one of the buttons is .shown in dotted lines. The disk 38 is mounted on the shaft 25 by means of a square aperture, like the contact buttons, and is provided with studs 89, 40, dia- Inctrically opposite each other and projectingl into the slots 86, 37. A paWl 4l., in the form of a blade spring, prevents countercloclrwise rotation of the ratrlfrt, liefen ring' to' Fig. 4- it will non' be appa rentVv that it' the finger button is turned clockwise, as indicated by the arrow, far enough to bring the contact plateA 30 into engagement ever so slightly with the cooperating terminal (thereby turning the contact button past tlie dead center, as previously explained) the slots will be turned at least to the,positions shown in dotted lines if not farther; but the instant such positions are reached the .spring terminals snap the button on to the closedcircuit position, the studs 39 Ll() moving in the slots Without further movement of the ratchet wheel. Similarly, if the button is .turned from the closed-circuit position far enough lto break the connection it Will have been turned past the dead center and the tension of the terminals will cause the 1noveshaped member 4Q; arranged in a eorrespondl ingly shapeddepression in theside Wall of the casing l0. On one side the depression has a recess to display the Words On l and 0th formed on the member 49., as shown in Fil. l. It desired, a similar lingeibutton can be' provided at the other end of the shaft 25, as shown at 34, thus making the switch more convenient in use.

lt. will be observed that the.mal e and .`breal are'always produced by a sliding movement of the Contact plates in engagement `With the terminal faces. thereby scraping` and grinding the two together and insuring clean bright contact-surfaces at all times.

The switch herein specifically illustrated is merely the preferred embodiment` and it is to be understood that the invention can be embodied in other forms without departure from its proper spirit and scope as defined by the following claims.

In describing the rotatable contact element. as elliptical in cross section I use the phrase merely as a short and convenient mode of expressingr the preferred form of the element, namely, a form in which the diameter in one direction is longer than the diameter at substantially right. angles to the first.

I claim i 1. The combination of a rotatable Contact element elliptical in cross-section and haiving axially spaced electrically connected eontactsurfaces on its opposite'sides; yielding terminals having contact faces bearing yieldingly on the opposite sides of the contact element to cooperate with said contact surfaces; means for connecting said terminals in an electric circuit; and means to ini- Losanna i 3 spring terminals Abearing yiel mgly on the opposite sides of the contact element to cooperate with the Contact surfaces and to impel the Contact element When the same is turned through. an appropriate angle; means for connecting the termina-ls in an electric circuit; and manual means to turn the Contact element through said appropriate angle and permit independent additional rotary movement by the impulse of the terminals. l

3. The combination of a plurality of yielding terminals and a rotary' Contact ele'- ment elliptical in cross-section, coperating to afford a` rotative impulse on the said element when the' same is turned through an appropriate angle; lcontacts on opposite faces of the contact element, extending past the shorter diameter thereoil from the oppositeA ends of the' longer diameter; an actu# atingr device to turn the rotary element in a given direction through such appropriateangle and permitting additional and independent rotation ofthe said element in the same direction; means to prevent reverse rotation of the rotary contact element; and means for connecting the terminals in an electric circuit.

4. In a snap switch, a rotatable Contact button elliptical in cross-section' and 'a contact extending from one end oi the longer diameter ofthe button past the lesser die ameter but terminating short of the other end ot' the longer diameter; in. combination u ith a yielding terminal bearing on the :tace of button; whereby the tension oi the terminal may ii'npel the button rotatively,when the button turned through an appropriate angle.

5. In a snap switch, a rotatable Contact member of substantially elliptical crosssection, in combination with a yielding terminal comprising a strip of spring metal' bent to zig-zag shape and to lobe-like form at itsv bends and having a face bearing on the rotatable member.

6. The combination of a rotary element elliptical in cross-section and having electrically connected axially spaced contact surfaces on opposite sides; yielding terminals bearing on the opposite sides ot the rotary member to cooperate With. the contact surfaces andcomprising strips ot spring iixelal. bent to zig-Zag form; means for conneet-ing the terminals in an electric circuit; and means to turn the rotary element through an aiiprolliriate angle and permit additional and independent rotary movement thereof.

7. The combination of a pair of rot-ary l coaxial Contact elements elliptical in crosssection, each having axially spaced elecsite sides; an insulating disk between the contact elements; yielding terminals, one for each of said contact surfaces, on oppositev sides of the contact elements and having faces to cooperate with said contact faces; means 'for connecting the terminals with electrical conductors; and means to impart rotary movement to thecontact elements.

8. In a snapswitch, the combination of a rotatable contact member elliptical in crosssection and having, on its opposite sides, electrically connected axially spaced contact surfaces extending from an end of the member an'd terminating short, of the othery end; yielding terminals consisting of strips of spring metal bent to zig-zag form and having faces to coperate with the contact elementvon opposite sides thereof; means for connecting the terminals in an electric circuit; manual means to turn the contact element on its axis; and means to permit rotation of the contact element in one direction only.

9. ln a snap switch','a resilient terminal; a rotary contact element elliptical in crosssection'and coperating with the terminal, whereby as the element turns on its axis the terminal is first compressed and then permitted to expand; means to turn the element on its axis and permit additional and independent rotary movement of said element by the force of the resilient terminal; means to permit rotation of said element in one direction only; and a contact surface on said element to coperate electrically with the terminal, the contact surface terminating short of an end of the contact element, whereby to bring the contact surface into electrical connection with the terminal the element must be turned past the point at which the terminal begins to expand.

10. The combination of a closed casing; parallel insulating bars inside thel casing and supported Tthereby; yielding terminals mounted on the said bars and extending inwardly therefrom; a shaft between the bars; a plurality of rotary contactbuttons elliptical in cross-section and mounted on said shaft, the buttons and terminals coperating to afford a rotative impulse on the former when they are turned through an appropriate angle; and meansoutside th'e casing to turn the buttons through such angle.

l1. The combination of a plurality of resilient terminals insulated from each other; a rotary contact element cooperating with the terminals to receive a rotative impulse therefrom When turned through an appropriate angle; contacts thereon terminating short of one' end of the longer diameter of trically connected contact surfaces on oppo v the coni act element; an inclosing and supporting casing provided with openings to adlnit, conductors; and means operable from outside the casing to rotate the Contact ele- Inent. y l2. The combination with parallel rows of terminals arranged side by side and insulated from each other; a shaft between and parallel witlirsaid rows of terminals;

r and a rotary Contact element elliptical in cross-section'mounted on `the shaft and cooperating wlth the terminals, the contact element haying pairs of axially spaced and 

